Monitoring boundary crossings in a wireless network

ABSTRACT

A process ( 400 ) according to one implementation of the present invention is initiated by receiving ( 402 ) a service zone definition for a boundary crossing. The boundary crossings application further receives ( 404 ) a monitoring request. For example, a vehicle rental company may enter the MIN/ESN of all mobile units associated with vehicles that are to be monitored, the timeframes during which the vehicles are to be monitored and the specific zones or boundaries with respect to which vehicle movement is to be monitored. Movements of the mobile unit or units of interest can then be monitored by receiving and storing ( 406 ) current location information, retrieving ( 408 ) prior location information for the mobile unit or units, and using ( 410 ) the current and prior location information to determine whether a service zone boundary has been crossed during the intervening time interval. Once a determination is made ( 412 ) as to whether a boundary crossing has occurred, the boundary crossing application may continue monitoring mobile unit location/movement and/or may generate ( 414 ) service information according to application parameters. The service information is then transmitted ( 416 ) according to application parameters. Such application parameters may specify the recipient, content and format of the service information.

FIELD OF THE INVENTION

[0001] The present invention relates generally to providinglocation-based services in a wireless network and, in particular, toproviding service information based on the crossing of a service zoneboundary by a mobile unit in a wireless network.

BACKGROUND OF THE INVENTION

[0002] A number of different types of location based serviceapplications have been developed or proposed for wireless networks,i.e., communications networks involving at least one wireless interfacebetween communicating devices. Generally, such applications determine orotherwise obtain location information regarding the location of a mobileunit under consideration, e.g., a wireless telephone, PDA, wireless dataterminal or the like—and provide service information based on the mobileunit location. Examples of location based service applications includeE911, local service information and location-based billing applications.In E911 applications, emergency calls are routed to a selecteddispatcher based on the location of origin of an emergency call.Location based service applications provide information regarding localservices such as hotels or restaurants based on a request entered via amobile unit. In location based billing applications, a rate for a callplaced or received by a wireless telephone is dependent on the locationof the phone, e.g., whether the phone is inside or outside of a “homezone” for the subscriber proximate to the subscriber's residence,business or other defined location. Various other applications have beenproposed or implemented.

[0003] Location based service applications generally involve comparing acurrent (or recent) location to predefined service zone definitions tomake either a binary determination (e.g., that the mobile unit is eitherinside or outside of a zone under consideration) or a matchingdetermination (e.g., that the mobile unit location matches or overlapsone or more stored zone definitions). In either case, at one or morerelevant processing steps, mobile unit location informationcorresponding to a particular time is compared to service locationinformation corresponding to one or more service zones, service providedlocations or other stored location information. Thus, in E911applications the mobile unit location at the time of placing an E911call may be compared to the dispatcher coverage zones of an emergencyresponse network. In local service information applications, thelocation of a mobile unit at the time of submitting, for example, alocal hotel information request, may be compared to a database of hotellocation information. The location of a mobile unit during a call may beused by a location based billing application to establish billingparameters for the call.

[0004] In addition, location based service applications generallyprovide service information in response to an input by a subscriber orother application user invoking the application. In the case of localservice information applications, the input is generally an explicitservice request entered via the mobile unit. In E911 or location basedbilling applications, the location based service application may beinvoked invisibly, from the perspective of the mobile unit, upon makinga call. In other cases, the input invoking the application to provideservice information based on the location of the mobile unit, isreceived from an application separate or remote from the mobile unitrequesting location based service information, e.g., identification ofcurrent mobile unit location. In such applications, the serviceinformation is nonetheless provided in response to an input requestinglocation-based services. That is, the trigger event generally is, fromthe perspective of the service application, a service request.

SUMMARY OF THE INVENTION

[0005] The present inventors have recognized that certain location-basedservice application functionality can be supported and enhanced bygenerating service information based on the location or movement of amobile unit rather than in response to a service request from asubscriber, separate application or other system user or based on othercriterion such as periodic reporting. In this manner, events associatedwith the movement of a mobile unit can be identified as may be desiredfor a variety of applications. Moreover, movement of an identifiedmobile unit relative to a geographic reference such as a service zoneboundary can be monitored with minimal user inputs or communicationsbetween a location managing system and an associated wireless locationbased service application.

[0006] According to one aspect of the present invention, a method isprovided for generating service information based on a location inputregarding a mobile unit under consideration. The method includes thesteps of: providing a location based services application running, atleast in part, on a processing platform of a wireless network; receivingan input identifying a location parameter to be monitored for a mobileunit; storing the location parameter; receiving location informationregarding the current location of the mobile unit; in response to thereceived location information, comparing the location information to thestored location parameter; and, based on the comparison, selectivelygenerating service information regarding the mobile unit. Generation ofservice information is thereby triggered by the received locationinformation and the associated comparison to a stored locationparameter. The service information can be transmitted to the monitoredmobile unit, another mobile unit, a network node remote from the monitormobile unit and/or a further application.

[0007] According to another aspect of the present invention, a mobileunit is monitored to identify attainment of a predetermined relationshiprelative to a geographic reference such as the crossing of service zoneboundary. The associated method includes the steps of: providing alocation based services application running, at least in part, on aprocessing platform of a wireless network; defining at least onegeographic reference for the application, where the reference can beused to identify attainment of a predetermined positional relationshipby the mobile unit; storing an identifier for the mobile unit or unitsof interest to a subscriber; monitoring a location of the mobile unit,using the application and the identifier of the mobile unit, to identifyattainment of the predetermined positional relationship; andtransmitting service information regarding the mobile unit in responseto the identified attainment of the predetermined relationship. Theinvention has particular advantages for providing service information inresponse to a flux of the mobile unit relative to the geographicreference such as traversing a service zone boundary. Thus, serviceinformation may be generated based on identification of a boundarycrossing or other location related change in status rather than indirect response to a service request from a system user or based on aperiodic or occasional polling process.

[0008] The above noted functionality can be used to support and enhancea variety of applications. In certain applications, it is desired toprovide notification when a mobile unit crosses a defined boundary. Forexample, a car rental company, or other fleet manager, may wish to benotified if a vehicle enters a proscribed area (e.g., crosses into aprohibited country) or exits a permitted area. Similarly, a parent,government official or other person in a position of authority may wishto monitor the movement of a child or other person or charge to insurethat such charge has not entered a prohibited area or left a permittedarea or area of confinement. In other applications, mobile unit locationmay be monitored relative to service zone boundaries to re-rate calls orto provide emergency or other service information to a subscriber uponentering a given service zone. In still other applications, a systemuser may wish to be notified when a mobile unit comes within a definedradius of a defined location, moves West, East, etc. of a definedlocation or attains a defined location in relation to the currentlocation of another mobile unit. In another type of application, theboundary or other geographic reference may be defined at, or close to,the time of the location comparison rather than being predefined asubstantial time prior to the comparison. For example, an applicationmay notify a subject mobile unit when it comes within a certain distanceof one or more other identified mobile units or vice versa. Such anapplication may be useful for helping friends or family members torendezvous.

[0009] The present invention advantageously allows for monitoringposition and movement of mobile units utilizing existing networkstructure. In this regard, location information for a mobile unit ofinterest can be obtained from a network assisted location finding systemwhere location is determined based at least in part on the position of amobile unit relative to a known location of a network structure, e.g.,cell location, cell sector, AOA, TDOA, a GPS assist receiver system, anetwork overlay location transceiver, etc. The use of such network basedlocation finding technologies allows applications in accordance with thepresent invention to service a variety of mobile units systems includingconventional wireless phones and other devices without dedicatedlocation equipment such as GPS transceivers. Thus, such applications cansupport a greater number of subscribers without specialized handsets orother subscriber equipment dedicated to location determination.Moreover, systems in accordance with the present invention can beimplemented at least in part on network structure such as processingplatforms associated with a network switch. For example, a locationmanagement system maybe associated with such a platform to receivelocation information, and provide notification information to a wirelesslocation application when a mobile unit under consideration attains apredetermined relationship relative to a stored geographic reference. Byutilizing such network structure, rather than implementing suchfunctionality on an on-board computer or other subscriber equipment, theassociated application can have convenient access to a centralizeddatabase which may be conveniently updated to provide more currentinformation. Moreover, implementing such applications in connection withexisting structure allows network providers, carriers and the like tomake enhanced services available to existing subscribers and to therebydistinguish themselves from competing service providers.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] For a more complete understanding of the present invention andfurther advantages thereof, reference is now made to the followingdetailed description, taken in conjunction with the drawings, in which:

[0011]FIG. 1 illustrates the representation of a service zone boundaryin accordance with the present invention using a cell-sector basedlocation finding technology;

[0012]FIG. 2 illustrates activity that may be deemed a service zoneboundary crossing in accordance with the present invention;

[0013]FIG. 3 shows a wireless network implementing the system of thepresent invention; and

[0014]FIG. 4 is a flow chart illustrating a preferred implementation ofthe present invention.

DETAILED DESCRIPTION

[0015] The present invention is directed to a method and system forproviding service information in a wireless network in response to andbased on a comparison of mobile unit location information to a storedgeographic reference information. The following description includes aninitial discussion of exemplary applications that are supported by thepresent invention, followed by a description of the preferred networkfor implementation of the invention and then a description of preferredprocesses for implementing the invention.

[0016] A. Applications

[0017] The present invention supports a number of applications whereservice information is generated in response to detection of a mobileunit attaining a particular position in relation to a geographicreference, e.g., detection of a service zone boundary crossing. A numberof examples of such applications are described below. It will beappreciated that many more examples are possible. Nonetheless, thefollowing examples illustrate that such applications can vary, forexample, with respect to the types of service information that aregenerated as well as how and to whom or what the service is reported.

[0018] One type of application where it may be desired to monitorboundary crossings relates to fleet management such as rental vehicletracking. Rental vehicles may be tracked to insure that the trackedrental vehicle is being used in accordance with the rental contract,e.g., that the vehicle is not being taken across certain nationalborders. Boundary crossings may be proscribed due to insurancelimitations, political/social considerations or other reasons. Therental company may therefore desire to receive notification whenboundary crossings occur. It will be appreciated that the rental companywould not necessarily require continual updates of vehicle locations(though some companies may choose to obtain such updates) but, mostimportantly for present purposes, will desire notification triggered bya boundary crossing event.

[0019] Such notification can be conveniently provided via a data networksuch as the Internet. In this manner, an official of the rental companymay receive a graphical or text notification identifying the monitoredvehicle and the boundary crossing event, e.g., “ID #nnn has crossedinto/out of the United States.” In response to such notification, therental company may contact the lessee (e.g., by car phone) remotelydisable the rental vehicle, assess a contractual penalty or take otherremedial measures.

[0020] As will be discussed in more detail below, such a boundarycrossing event can be identified using a conventional wireless telephoneor other mobile unit carried by the rental vehicle and, preferably,configured to remain powered on when the vehicle is in use. Such amonitoring application can take advantage of existing wireless networkplatforms and location finding equipment to provide monitoring withminimal, if any, equipment on board the rental vehicle dedicated toposition monitoring, thereby reducing costs and facilitating rapiddeployment. As described below, a wireless network platform remotely orlocally associated with a network switch can be connected to one or morelocation finding equipment systems for receiving location informationregarding the monitored vehicle or its on-board mobile unit and can befurther connected to a data network for providing reports to the rentalcompany's data terminal.

[0021] Another type of application where it may be desired to monitorboundary crossings is location based billing applications. In theseapplications, the rate applied for calls placed or received using awireless telephone depends on the location of the phone. For example,wireless carriers may wish to encourage subscribers to use theirwireless phones as their only phones by providing call ratingcompetitive with land line phones for calls placed in or near thesubscriber's home, office or other defined location, but providing adifferent rating for calls placed or received outside such “home zones.”The relevant rating information may be provided to a billing system ofthe carrier or other service provider by populating an associated fieldof a Call Detail Record (CDR) with a billing value.

[0022] In connection with such applications, it may be desired tomonitor boundary crossings for a number of reasons. For example,identifying crossings into or out of a home zone may be used to re-ratean ongoing call or otherwise re-set a billing parameter. Also, it may beuseful to provide an indication to the subscriber regarding locationrelative to a home zone, e.g., via a display element on the handset, sothat the subscriber can know in advance of a call what rates may apply.Thus, boundary crossings may be monitored in order to transmit messagesto the mobile unit causing the display element to toggle between “homezone” and “outside home zone” displays. In the case of call re-rating, asingle call may be divided into parts billed at different rates, e.g.,by generating multiple CDRs, or a single rate may be selected based on aboundary crossing. In either case, the service information provided bythe application may simply be a rating value and the recipient may be abilling application.

[0023] A final example of applications that may make use of boundarycrossing information is a local service or friend notificationapplication. Such an application may provide emergency information—e.g.,regarding local traffic, weather, or other emergency conditions—or otherservice information—e.g., information about local hotels, restaurants orother services—to all or subscribing system users upon entry into aservice area. For example, in the case of severe weather warnings, atraveler may be notified by phone or display upon entering the affectedarea (such as on crossing a county line). For a traffic jam, warningsand alternative route or other information may be provided to commuterscoming within a certain area encompassing the problem location.Similarly, local service providers may transmit pricing, event or otherservice information to willing, approaching travelers. In the case of“friend” notification, a subscribing system user and/or an identified“friend” may be notified when the user comes within a certain proximityof the mobile unit of the friend or the friend comes within a certainproximity of the user. In such cases, the “boundary” may be defined andredefined “on the fly”.

[0024] In such cases, service information may be transmitted to themonitored mobile unit, an associated data terminal or other deviceproximate to the monitored unit. The information may be provided inaudio, text, graphical or other form depending, for example, on thelimitations of the user equipment and the type of information required.Transmission of the service information may be triggered by crossing apolitical or government boundary, crossing within a radius of a locationof interest or otherwise crossing a service zone boundary of any shape.

[0025] As the foregoing examples illustrate, the type of serviceinformation, form of service information transmission, intendedrecipient and other details can vary from application to application oreven within a particular application in accordance with the presentinvention. This will be further understood upon consideration of apreferred network environment of the present invention as describedbelow.

[0026] B. Network Environment

[0027] The present invention can be implemented in a wirelesscommunications network such as a wireless telephone network. Such animplementation has a number of advantages. First, in many cases,wireless networks have access to location information regarding mobileunits located within the wireless network or certain areas thereof fromexisting location finding equipment. In many cases, such locationfinding equipment is capable of providing location information for anymobile unit within the coverage area. Moreover, certain location findingtechnologies can provide location information without requiring anyspecialized subscriber equipment dedicated to location finding. Inaddition, the present invention can make use of existing networkstructure such as processing platforms and switching equipment to accesslocation information, perform location calculations as desired and routeservice information to system users. In this manner, a system forproviding service information in accordance with the present inventioncan be readily implemented. Moreover, such services can be marketed towireless network subscribers, and service providers who desire access tosuch subscribers, thereby facilitating system deployment and enablingwireless carries to provide a value added service that may distinguishthe carrier from competitors.

[0028] Various types of location finding systems can be used inaccordance with the present invention. Preferably, the location findingsystem is a network assisted technology such as AOA, TDOA, networkassisted GPS, cell sector or similar network based system thereby makinguse of existing technology associated with the wireless network. In oneembodiment, the location finding system employed is a fully networkbased system such as a cell sector system that provides locationinformation regarding a mobile unit of interest without requiring anymobile unit based equipment dedicated to location determination. Inaddition to cell sector technology, such systems included AOA, TDOA andthe like.

[0029]FIG. 1 illustrates a wireless network 100 utilizing a cell sectortechnology to represent a service boundary 108. The network 100 includesa number of cell sites 102 each having an associated coverage area 104within which cell site equipment can communicate with mobile units viaRF signals. As shown, the coverage areas 104 of each cell may beirregular in shape due to, for example, local geography and other localsignal transmission characteristics. Moreover, the coverage areas 104may overlap as shown to insure relatively complete coverage. Coverageareas may also overlap in order to provide better service in high usageareas of the network.

[0030] A cell site 102 may include a number of directional antennas thateffectively divide the coverage 104 into a number of sectors 106. In theillustrated embodiments, individual cells are divided into three sectors106, each of which covers approximately 120 degrees of the coverage area104 surrounding the cell site 102. Thus, each sector 106 encompasses agenerally wedge-shaped area.

[0031] A location finding system utilizing cell sector technologyprovides a somewhat coarse indication of mobile unit location. Inparticular, the location of a mobile unit is approximately known bydetermining which cell sector antenna is handling communications withthe mobile unit. Based on this information, the mobile unit is deemed tobe within the associated generally wedge-shaped area. For processingpurposes, the associated location may be expressed as a two-dimensionalcoordinate location, e.g., representing a center point of the generallywedge-shaped area, and an uncertainty area, e.g., defined by anuncertainty radius. Such an uncertainty radius may be selected toreflect the uncertainty inherent in the cell sector technology. It willbe appreciated that alternative location finding technologies mayprovide greater accuracy. For example, AOA, and TDOA methodologies arecapable of providing greater accuracy than cell sector technologies.Moreover, in areas of a wireless network where more than one locationfinding technology is available, location information from multiplelocation finding technologies, or the raw location information fromwhich location determinations are made using one or more of thetechnologies, may be combined to provide even greater accuracy.

[0032] In FIG. 1, the dashed line 108 represents a service zoneboundary. For present purposes, the area to the right of the servicezone boundary 108 may be taken to define a service zone such as a zonewithin which authorities wish to disseminate emergency information. Inthe illustrated network 100 which utilizes a cell sector based locationfinding technology, the boundary 108 and associated service zone areapproximated by a set of cell sectors. These cell sectors are the shadedsectors 106 in FIG. 1. It will thus be observed that the shaded cellsectors 106 generally coincide with the service zone, although theboundary 108 is only followed imperfectly. In the illustrated example,the service zone definition depicted by the shaded cell sectors is overinclusive in that any cell sector that is at least partially within theservice zone is included in the service zone definition. As a practicalmatter, this means that any mobile unit that may or may not be withinthe surface zone due to the uncertainty inherit in the cell sectortechnology may be deemed to have crossed the boundary 108 and maytherefore receive the emergency information.

[0033] More specifically, the system of the present invention canprovide service information based on a boundary crossing determinationas opposed to, for example, a binary determination that a mobile unit iseither inside or outside a service zone at a particular instant in time.This is illustrated in FIG. 2. In FIG. 2, the location of a mobile unitis indicated by a point, e.g., defined by two-dimensional coordinates,and an uncertainty area 102. In the illustrated implementation, theuncertain area is taken to be defined by an uncertainty radiussurrounding the point 200, but it should be appreciated that uncertaintyareas of other shapes may be utilized. In FIG. 2, a current location ofa mobile unit is shown in solid lines and a prior location of the mobileunit is shown in dashed lines. The presumed movement of the mobile unitbetween the two times is therefore indicated by arrow 206.

[0034]FIG. 2 illustrates activity that may be characterized as aboundary crossing. In particular, reference numeral 204 indicates aservice zone boundary. In this case, the boundary 204 defines a servicezone of complex shape as may be desired in a particular application. Atthe first time, the location of the mobile unit as indicated by thepoint 200 and the uncertainty area 202 is fully located on a first sideof the boundary 204. At the second time, the location of the mobile unitas indicated by the point 200 and the uncertainty area 202 isundetermined with respect to the boundary 204. That is, a portion of theuncertainty area 202 at the second time overlaps a portion of theservice zone. Accordingly, the mobile unit may be within the servicezone. This change in status from the first time to the second time(i.e., from “outside” the service zone to “potentially inside”) may bedeemed a boundary crossing event for the purposes of a particularapplication. It will be appreciated that a boundary crossing event maysimilarly be indicated by a change in status from clearly outside theservice zone to clearly inside the service zone, i.e. where the entireuncertainty area at the second time is within the service zone.

[0035] The example of FIG. 2 suggests one mathematical analysis foridentifying a boundary crossing event. Specifically, a change in statusbetween the first time and the second time is determined relative to anoverlapping area analysis. At the first time, the area of overlapbetween the uncertainty area 202 and the service zone is a mathematicalnullity. At the second time, there is an intersection between a set ofarea units comprising the uncertainty area 202 and the set of area unitscomprising the service zone. For example, the area units may be elementsof a Quadtree data structure utilized to represent the area of awireless network such as described in co-pending U.S. patent applicationSer. No. 09/788,036 which is incorporated herein by reference in itsentirety.

[0036] It will be appreciated that a variety of other mathematicalmodels may be utilized in accordance with the present invention toidentify a boundary crossing relative to first and second locationinformation. For example, a first mathematical representation may bedefined to represent a line segment or other geometric elementinterconnecting the first point 200 (associated with the first time) andthe second point 200 (associated with the second time) or the first area202 and the second area 202 and a second mathematical representation maybe utilized to define the boundary 204. These mathematicalrepresentations may then be compared e.g., by simultaneously solvingequations, to identify any intersection. Alternatively, a ray may bedefined emanating from the point 200 at the first time in a selecteddirection. Another ray may be defined emanating from the point 200 atthe second time in the same or a different direction. At each time, thenumber of instances that the ray crosses the boundary 204 may bedetermined to thereby provide an indication that the point underconsideration is inside or outside of the service area. Any change instatus in this regard between the first time and the second time wouldbe indicative of a boundary crossing. Many other solutions are possibleas will be appreciated as one skilled in the art.

[0037] For many applications, identifying a boundary crossing mayprovide advantages relative to generating service information based on abinary determination that a mobile unit is located within or outside aservice area at an instant in time. For example, it may be desirable toprovide emergency information or local service information only uponentering a service zone rather than continuously while a mobile unit islocated within a service zone. This objective can be achieved bytriggering transmission of the service information based on a boundarycrossing rather than based on a determination that the mobile unit isinside of the service zone. Moreover, in other contexts, transmissionsbetween a network platform and a mobile unit may be reduced therebyconserving bandwidth. For example, as noted above, in a location basedbilling application, it may be desirable to provide an indication on adisplay of the mobile unit indicating that the mobile unit is eitherinside or outside of a home zone. Such information may be transmittedfrom a network platform to a mobile unit. In order to minimize suchtransmissions, updated information may be transferred to the mobile unitonly upon a change in status with regard to the home zone boundaries.

[0038]FIG. 3 illustrates a wireless network 300 implementing the presentinvention. In the network 300, a mobile unit 302 communicates with cellsite equipment 304 via an RF interface. In the illustrated example, themobile unit 302 is shown as being a wireless telephone. It will beappreciated, however, that any suitable mobile unit can be utilizedincluding, for example, personal digital assistants, data terminalshaving a wireless modem, etc. The cell site equipment 304 may be, forexample, a cell sector antenna or the like. In the illustrated network300, the cell site equipment 304 is interconnected to a switch 306.Although only one piece of cell site equipment 304 is illustrated, itwill be appreciated that switch 306 may service multiple cells. Theswitch 306 may be, for example, a mobile switching center (MSC) or anyother structure for routing communications between a calling unit and acalled unit. As will be discussed in more detail below, the switch 306may also be operative for generating billing records such as Call DetailRecords for transmission to a billing application of a wireless carrieror other service provider.

[0039]FIG. 3 also shows a platform 308 associated with the switch 306.The platform 308 may be, for example, a computer platform for executinga variety wireless network applications. The platform 308 may bephysically located proximate to the switch 306 or may be remotelylocated and interconnected to the switch 306 by a local area network,wide area network or other communications pathway. The illustratedplatform 308 includes a microprocessor 310 for running a boundarycrossings application in accordance with the present invention. As willbe understood from the description below, a boundary crossingsapplication in accordance with the present invention may be a fullyself-contained application for receiving location information,identifying a boundary crossing and providing service information inresponse to the boundary crossing in the form desired by the end user.Alternatively, a boundary crossings application in accordance with thepresent invention may function as a module to identify a boundarycrossing and provide information regarding the boundary crossing forfurther processing by another application. In order to identify boundarycrossings, the boundary crossing application running on processor 310can access service zone information and location information. Theservice zone information provides a definition of service zones for useby the application. These definitions may be provided in any suitableform. For example, a service zone may be defined as a set of cellidentifiers or cell sector identifiers that represent the service zone.Alternatively, the service zone information may be stored as a set ofgeographical coordinates or geographical boundaries that define theservice zone. For cell sector implementations, such geographicalinformation may be converted into current network topology, e.g., cellsector identifiers, at the time of a boundary crossing determination. Itwill be appreciated that other conventions may be utilized for storing arepresentation of a service zone area. In addition, it will beappreciated that a GIS system may be utilized for inputting andformatting the service zone information. For example, a service provideror other person defining a service zone may wish to input service zoneboundaries relative to an address, streets or other topologicalinformation. A GIS application, such as the MAPS application marketed bySIGNALSOFT Corporation of Boulder, Colo., may be utilized to receivesuch inputs and convert the associated service zone definitions intogeographical information formatted for convenient handling by theboundary crossing application. Thus, service zone definitions may beconverted from one topological system, e.g., addresses or streetboundaries, to another topological system, e.g., geographicalcoordinates or cell/cell sector identifiers.

[0040] Location information regarding the locations of mobile units mayalso be stored for access by the boundary crossings application.Depending, for example, on the nature of the location finding technologyemployed, the nature of the received location information and the routeby which the information is obtained may vary. For example, in the caseof cell sector location information, a cell sector identifier may beextracted from communications between the mobile unit 302 and the switch306. In the case of handset-based location finding equipment such as GPSinformation, location coordinates may be encoded into communicationstransmitted from the unit 302 to the cell site equipment 304. In othercases, raw location information may be preprocessed by a locationmanagement program running on the platform 308. In any case, inaccordance with the present invention, location information may bestored in location cache 314 so as to enable later use in a boundarycrossing analysis such as comparison of mobile unit location informationfor a first time and a second time.

[0041] In the illustrated embodiment, the platform 308 is illustrated ashousing a service zone database 312 and a location cache 314. Such aservice zone database 312 may include service zone definitions for oneor more applications. The location cache 314 may include locationinformation for mobile units at various times indexed, for example, to amobile unit identifier such as a MIN/ESN. Although the database 312 andcache 314 are thus illustrated as distinct elements, it will beappreciated that the database 312 and cache 314 may utilize shared ornon-dedicated memory resources. Moreover, the database 312 and cache 314need not be located on the platform 308 or on the same machine as oneanother, but rather, may reside at any location where the storedinformation can be accessed by the boundary crossing application.

[0042] As noted above, depending on the specific application and otherfactors, the resulting service information can be transmitted todifferent recipients via different pathways. For example, in the case ofthe above noted rental vehicle tracking application, the resultingservice information is provided to a data terminal at a rental companyremote from the monitored mobile unit. To support such applications,service information can be transmitted from the illustrated platform 308to a data network node 320 via a data network 318 such as the Internet.In other applications, such as re-rating for location based billingapplications, the recipient of the service information is anotherapplication such as a billing application that is registered with theboundary crossings application to receive service information, e.g.,related to boundary crossings. In the case of the location based billingapplication, the service information may be a billing value of a CallDetail Record (CDR). In such a case, the service information may betransmitted to application 322 by way of the switch 306. In other cases,such as the above noted emergency service or local service applications,it is desirable to transmit the service information to the monitoredmobile unit 302. In such cases, the service information may betransmitted to the unit 302 via the switch 306 and cell site equipment304.

[0043] The service information may be presented in various forms. Forexample, service information may be transmitted to the mobile unit 302via a short messaging system for providing an audio message that can beplayed on the unit 302. Alternatively, a text message may be displayedon a LED display or other display of the mobile unit 302. As previousnoted, an output may be provided to an application 322 such as a billingapplication by populating a field of the CDR. In other applications, anaudio, text and/or full graphics presentation (e.g., a graphical mapshowing mobile unit location) may be provided at a data network node320. It will thus be appreciated that the boundary crossings applicationmay utilize appropriate hardware, firmware and/or software for providingthe service information in the appropriate format and in accordance withappropriate protocols. Thus, the information may be packetized fortransmission across the Internet in accordance with IP protocols. Datamay also be transmitted to the mobile unit 302 utilizing proxies,microbrowser and other elements for executing wireless datacommunications protocol. Similarly, in the case of a CDR output, the CDRmay be populated in accordance with telecommunications networkprotocols.

[0044] C. Process Implementation

[0045]FIG. 4 is a flowchart illustrating a process 400 for implementinga boundary crossings application in accordance with the presentinvention. The process 400 is initiated by receiving (402) a servicezone definition for the application. As noted above, the nature of theservice zones can vary from application to application. The servicezones or associated boundaries may include political or governmentboundaries, street or other topological data, geographical coordinatesand associated cell sector identifiers or other zone delineators orother geographical information. Such information may be input using GISapplication or by other means.

[0046] The boundary crossings application further receives (404) amonitoring request. For example, a vehicle rental company may enter theMIN/ESN of all vehicles that are to be monitored, the timeframes duringwhich the vehicles are to be monitored and the specific zones orboundaries with respect to which vehicle movement is to be monitored.Similar types of information may be entered by parents or governmentofficials wishing to monitor movements of individuals or by wirelesscarries or network subscribers relating to bill zones. The boundarycrossings application can then monitor movements of the mobile unit orunits of interest by receiving and storing (406) current locationinformation, retrieving (408) prior location information for the mobileunit or units, and using (410) the current and prior locationinformation to determine whether a service zone boundary has beencrossed during the intervening time interval. This monitoring cancontinue throughout a time period as specified by a network user. Withregard to the process for monitoring location, the system user mayspecify a frequency for monitoring if desired. Thus, for example, arental car company may request position updates every ten minutes or atsome other interval. At each such interval, the boundary crossingsapplication may access the most recent information available in thelocation cache or may invoke the location finding equipment to obtaincurrent information. It will be appreciated that different frequenciesmay be useful for different applications. Alternatively, the boundarycrossings application can be programmed to make a boundary crossingdetermination each time new location information is received for amobile unit of interest. In this regard, it will be appreciated thatsuch location information may be obtained as a result of a periodicpolling process in connection with normal network administration.

[0047] The process of using the current and prior location informationto identify boundary crossings may utilize the two most recent instancesof location information for a particular mobile unit, or may utilizelocation information for other times. Moreover, in certain cases, suchas in the case of GPS information, location information for a particulartime may be coupled with travel direction and speed information. Suchtravel direction and speed information may also be obtained byprocessing location information for a particular mobile unit at two ormore times. In such cases, tracking information may be used to identifyor predict a boundary crossing without relying on a change of status asbetween first and second location information and first and second timesrelative to a zone boundary. Once a determination is made (412) as towhether a boundary crossing has occurred, the boundary crossingapplication may continue monitoring mobile unit location/movement and/ormay generate (414) service information according to applicationparameters. In the latter regard, the boundary crossings application maybe programmed to output a billing parameter, retrieve and transmitprerecorded service information, or otherwise output service informationdepending on the specifics of the program. The service information isthen transmitted (416) according to application parameters. Suchapplication parameters may specify the recipient, content and format ofthe service information as discussed above.

[0048] While various embodiments of the present invention have beendescribed in detail, it is apparent that further modifications andadaptations of the invention will occur to those skilled in the art.However, it is to be expressly understood that such modifications andadaptations are within the spirit and scope of the present invention.

1. A method for use in providing services based on the locations ofmobile units in a wireless communications network, said wireless networkincluding a switch structure for use in selectively routingcommunications between network users and a processing platformassociated with the switch structure, said method comprising the stepsof: providing a location based services application running, at least inpart, on the processing platform associated with the switch structure;defining at least one geographic reference for said location basedservices application; storing an identifier for a mobile unit ofinterest to a user; monitoring a location of said mobile unit, usingsaid location based services application and said identifier of saidmobile unit, to identify an attainment of a predetermined relationshipof said mobile unit relative to said geographic reference, saidattainment being defined by a change of status with respect to saidpredetermined relationship; and transmitting service informationregarding said mobile unit in response to said attainment of saidpredetermined relationship of said mobile unit relative to saidgeographic reference.
 2. A method as set forth in claim 1, wherein saidstep of defining said geographic reference comprises receivingsubscriber specific information from said user regarding said geographicreference and said step of storing comprises indexing informationregarding said geographical reference to said identifier.
 3. A method asset forth in claim 1, wherein said step of defining comprisesidentifying a geographical area for which said user desires to receivenotification upon one of: a) entry of said mobile unit into saididentified geographical area; and b) exit of said mobile unit from saididentified geographical area; and said step of transmitting comprisesproviding notification to said user of said boundary crossing event. 4.A method as set forth in claim 1, wherein said step of definingcomprises receiving zone location information regarding a service zonereferenced to a first topology system and expressing said zone locationinformation in terms of a second topology system of said location basedservices application.
 5. A method as set forth in claim 4, wherein saidfirst topology system comprises a street grid.
 6. A method as set forthin claim 4, wherein said second topology system comprises one of ageographical coordinate system and a system of wireless networksubdivision identifiers.
 7. A method as set forth in claim 1, whereinsaid step of providing a location based services application comprisesproviding an application for allowing a person of authority to monitorthe movements of one of a person or a vehicle associated with saidmobile unit.
 8. A method as set forth in claim 1, wherein said step ofproviding a location based services application comprises providing anapplication for setting a billing parameter for use of said wirelessnetwork by said mobile unit.
 9. A method as set forth in claim 1,wherein said step of monitoring comprises storing first locationinformation regarding a first location of said mobile unit at a firsttime, obtaining second location information regarding a second locationof said mobile unit at a second time and comparing said first locationinformation to said second location information to identify saidattainment of said predetermined relationship.
 10. A method as set forthin claim 9, wherein said first location information comprises a firstzone identifier for a particular service zone and said second locationinformation comprises a second zone identifier for a particular servicezone, and said step of comparing comprises determining whether saidfirst zone identifier is the same as said second zone identifier.
 11. Amethod as set forth in claim 9, wherein said step of monitoring furthercomprises defining a geometrical element interconnecting a firstlocation of said first location information and a second location ofsaid second location information and determining whether there is anintersection between said geometrical element and a boundary of aservice zone.
 12. A method as set forth in claim 1, wherein said unit isa telephone and said step of storing an identifier comprises storing anMIN/ESN.
 13. A method as set forth in claim 1, wherein said step oftransmitting service information comprises transmitting said serviceinformation to said mobile unit.
 14. A method as set forth in claim 1,wherein said step of transmitting service information comprisestransmitting said service information to a data network node associatedwith said subscriber, said data network node being separate from saidmobile unit.
 15. A method as set forth in claim 1, wherein said step oftransmitting service information comprises transmitting said serviceinformation to a separate application that is registered with saidlocation based services application to receive boundary crossinginformation regarding said mobile unit.
 16. A method as set forth inclaim 1, wherein said step of transmitting service information comprisestransmitting a message to said user providing notice of a boundarycrossing event.
 17. A method as set forth in claim 16, wherein saidmessage comprises one of a voice, text or graphical message.
 18. Amethod as set forth in claim 1, wherein said step of transmittingservice information comprises transmitting one of local serviceinformation and local emergency condition information to said mobileunit.
 19. A method for use in providing services, based on the locationsof mobile units in a wireless network, comprising the steps of:establishing a location based services system, including a processingplatform and data storage associated with the processing platform; saidlocation based services system being interconnected to a networklocation finding system for receiving network location informationtherefrom regarding the location of the mobile units within the wirelessnetwork, said network location finding system being operative fordetermining said network location information regarding said mobileunits based on locations of the mobile units and known locations ofnetwork structure in said wireless network; said location based servicessystem further being interconnected to a system user via a communicationnetwork including a switch structure for routing communications based onan address whereby user information can be transmitted from saidlocation based services system to said user by associating said userinformation with a user address; said location based services systemfurther being associated with a data input port for receivinginformation for storage in said data storage and for use by saidlocation based services system; first receiving, via said data inputport, service zone information identifying a geographic service zoneincluding at least one service zone boundary; first storing said servicezone information in said data storage of said location based servicesystem; second receiving, via said data input port, an identifieridentifying a mobile unit of interest to said system user; secondstoring said identifier in said data storage of said location basedservice system; third receiving, from said network location findingsystem, said network location information including mobile unit locationinformation regarding said mobile unit of interest; third storing saidmobile unit location information in said data storage of said locationbased service system; first operating said location based service systemto 1) monitor locations of said mobile unit of interest over a timeperiod, 2) make a comparison based on one or more of said monitoredlocations of mobile unit location to said service zone boundary, and 3)based on said comparison, identify a crossing of said service zoneboundary by said mobile unit of interest; and second operating saidlocation based service system to 1) generate service information inresponse to said identified crossing of said service zone boundary, 2)establish a user communication including said service information andinformation identifying said user address, and 3) transmitting said usercommunication to said system user; wherein said system user receivesservice information triggered by said crossing of said service zoneboundary.